The present invention relates to an interactive electronic device having a bus with digital and analog data links and a method for transmitting digital data and an associated analog signal along the bus when any of a plurality of removable electronic cartridges is operatively coupled to the bus.
Interactive electronic devices, and more particularly, hand-held interactive consumer electronic devices used for learning and amusement typically have digital signal processing architectures with a limited amount of internal memory which at best may be expanded with memory cartridges removably receivable in externally accessible cartridge slots. By use of the removable memory cartridges, additional software programs and associated data may be added to expand the functional capabilities of the devices. One example of such a device is the Super Speak & Read™ manufactured by Texas Instruments Inc., Dallas, Tex. The Super Speak & Read is an interactive book system with a base that is configured as a folding book that allows a child to activate speech and sounds by touching language symbols and images in multi-page activity books that are removably insertable in a book area in the base. The speech and sounds are synthesized from audio data stored in digital memory in the base unit and may be augmented with additional memory cartridges that are insertable in one of two external cartridge slots in the base unit.
As consumers have become accustomed to increasingly sophisticated, feature laden interactive devices with high quality audio and video user interfaces, substantial amounts of data at increasingly higher data rates must be transmitted from the external cartridges to the system electronics. Typically, such data transfers occur over a digital interface resulting in a substantial increase in the unit cost of both the cartridges and the devices themselves.
In certain applications, analog transmission of audio signals is potentially more cost effective than current digital methods and may allow manufactures of interactive electronic devices in the consumer electronics market to achieve a lower price point.
Accordingly, there is a need in the art for interactive electronic devices and, more particularly, for hand held interactive electronic devices used for learning and amusement to have the capability of providing external removable memory cartridges that operatively couple to the device by both a digital and analog data links.